Term | Definition |
Frederick Griffith | In 1928, British Scientist who wanted to know how bacteria made people sick. |
S strain | Harmful bacteria, smooth edges |
R strain | Harmless bacteria, rough edges |
Griffith's experiment results | Transformation = one type of harmless bact. permanently changed into another harmful bact. |
Oswald Avery | In 1944, Canadian Scientist wanted to determine which molecule in the heat-killed bacteria was most important for transformation. |
Avery's experiment | Extracted a mixture of various molecules from the heat killed bacteria. They treated the mixture with enzymes that destroyed proteins, lipids, carbohydrates, and nucleic acids |
Avery's experiment results | Transformation still occurred
Except…. When DNA was detroyed. Transformation could NOT occur |
Hershey and Chase | Studied Viruses - specifically viruses that infect bacterica |
3 Roles of DNA | Store Information
Copy Information
Transmit Information |
DNA must do 3 Things | Carry Information from one generation to the next
Determine heritable Characteristics
Be easily replicated for mitosis to occur |
What is DNA made up of? | Made up of units called nucleotides |
Basic Parts of DNA (3) | Phosphate Group
5-Carbon Sugar (deoxyribose)
Nitrogen Containing Base |
Chargaff's Rule | A=T and G=C |
Rosaline Franklin | Used X - Ray diffusion to give clues about DNA structure. She stretched DNA fibers and aimed a powerful X-ray beam that formed the scattered pattern picture showing a twisted structure of 2 strands. |
Watson and Crick | Used Chargraffs rule and Franklin's picture to build a structural model of DNA. |
Double Helix | 2 strands that are wound around each other looking like spiral staircase. |
Hydrogen Bonds | Holds strands of DNA together |
A-T | Double bonded |
G-C | Triple bonded |
What features a sugar phosphate backbone? | DNA Structure |
DNA molecules separate into ________ strands and then produces two new___________ strands following the rules of base pairing | 2 strands ; 2 new strands |
Before a cell divides, it duplicates its DNA in a copying process called ___________________ | Replication |
S Phase | When DNA replication occurs |
DNA polymerase | Principle enzyme involved in DNA replication
"Proofreads" each new strand |
Prokaryotes | Single circular DNA in cytoplasm |
Eukaryotes | Have 1000 times more DNA than prokaryotes; has DNA in the nucleus |
Prokaryotic Replication | Starts from a single point and proceeds in 2 different directions until the entire chromosome is copied. |
Eukaryotic Replication | Begins at dozens or even hundreds of places on the DNA molecule, proceeding in both directions until each chromosome is copied. |
Proteins | Check for chemical damage or base pair mismatches before replication. |
RNA | Ribonucleic Acid |
DNA | Deoxyribonucleic Acid |
How is RNA different from DNA? | RNA is single stranded
Contains ribose instead of deoxyribose
Contains uracil instead of thymine |
DNA = "_____" | "Master Blueprint" |
RNA = "_____ " | "Disposable Copy" |